This invention relates to an instrument for testing air or other gaseous bodies, and more particularly pertains to a portable hand-operable testing device for detecting the presence of germs, bacteria and other foreign bodies in large gaseous volumes.
Although the prior art has employed testing devices of the general type hereinafter described, they have heretofore been subject to a serious shortcoming, namely the inability to detect the presence of minute bodies such as germs in large gaseous volumes. The many prior art testing devices which perform quantitative and qualitative analyses of contaminants in the ambient atmosphere have performed with inconsistency. A common assumption employed in testing gaseous volumes, i.e., that germs or other contaminants collected are equally distributed in the atmosphere has been proved to be invalid.
Thus a test of a small portion, e.g. a cubic meter, of a large room for germs will not provide a basis for determining, with any degree of accuracy, the germ content of the entire room. Many prior art testing devices employ small air intake ports which result in the testing of a limited air mass immediately adjacent the intake ports. Conceivably undetected clouds of germs may be in the atmosphere adjacent the limited volume passing through the testing device.
Undetected germs such as those of the Clostridium group can be very dangerous and under certain circumstances fatal. It is thus apparent that testing devices should test large air or other gaseous volumes in the shortest time possible to minimize lack of detection of foreign bodies present.
The necessity for constant atmosphere surveillance is apparent in applications such as the manufacturing and packaging of medicines, pharmaceuticals and the like, food processing plants, in hospitals and other institutions where the aged and/or infirm are present and strict hygienic conditions are to be maintained.
In one embodiment of this invention, the device comprises a battery-operable motor housed in a casing similar to a flashlight casing. Cultural media is disposed in a shallow cup or agar drum attached to one end of the casing, and a motor-driven shaft passes through a central opening in the cup bottom and a plurality of rotatable blades extending from a central hub is mounted on the shaft end. The cup has disposed on its bottom portion surrounding the central aperture and about its inner wall periphery, cultural media adapted to foster the growth of foreign substances whose presence is to be determined. A finger actuatable switch energizes the device motor causing the shaft-driven blades to impel the surrounding atmosphere against the cultural media disposed in the cup. The cultural media is preferably in the form of discrete sections adapted to foster the growth of various specific germs or other foreign substances.
It is thus an object of this invention to provide a hand portable, finger actuatable testing instrument in which a large volume of air or other gas is tested for foreign substances in a short period of time.
It is another object of this invention to provide a testing device which is composed of readily replaceable elements of low cost which may be carried by hand into an area to be tested.
It is a still further object of this invention to provide a testing device which is flexible in operation so as to simultaneously test for a variety of substances in the ambient atmosphere.